The boilers at the Astoria Houses in Queens were barely able to heat the building to 68 degrees, forcing NYCHA officials to deploy a mobile boiler.

The city was blanketed with snow, plunged into days of record low temperatures — and in many NYCHA developments across the city, the heat wasn’t working.

At some developments, the oil powering the boilers froze. At others, it was the gas pressure equipment that fuels the boilers that froze. At still others, it was pipes to mobile boilers — used to heat developments where the boiler rooms are so old they’ve been condemned.

Even when the behemoth boilers, decades old and well past their prime, were working fine, some simply couldn’t keep up with the cold.

“Imagine if your car had 300,000 miles on it, right? The thing is always in the shop, and you’re always afraid to take it on a trip,” Robert Knapp, director of heating at the New York City Housing Authority, told the Daily News.

“Boilers are the same thing. When they’ve passed their lifespan, and they’ve ran for tens of thousands or hundreds of thousands of hours, they start to wear out.”

When they do, it’s Knapp’s job to make sure the heat gets back on. After outages earlier this month during the long cold snap left thousands of tenants without heat, Knapp had to explain to the mayor what his crew is up against as they race to get boilers back online only for other ones to fail.

From left to right: Robert Knapp, NYCHA's director of heating, joins Heating Management Services Department field superintendents Anthony Rivera and Marco Acevedo, at the Astoria Houses' mobile boiler on Tuesday.

“Every year my operating budget goes up. I was given $12 million last year to manage these boilers and we spent every dime of it,” Knapp said. “I could have easily spent $24 million. Because it’s not enough, right?”

On Tuesday, Knapp was at the Astoria Houses in Queens, where two of his right-hand men, field supervisors Marco Acevedo and Anthony Rivera, were fixing a flame failure on a mobile boiler in the parking lot.

The team deployed the mobile boiler during the cold snap. While all four permanent boilers at the Astoria Houses were up and running, they were barely able to heat the building to 68 degrees, Knapp said. And while some developments have a redundancy — an extra boiler that kicks in if one fails — Astoria doesn’t.

The Astoria Houses' mobile boiler suffered a flame failure.

Rivera and Acevedo are part of a “special teams” crew that reports directly to Knapp. The team triages boilers across the city and is tasked with ensuring everything is in order after a local supervisor has made repairs.

All three men grew up in NYCHA buildings — Knapp in Staten Island’s Berry Houses, home to 1954 boilers, Acevedo in Breukelen Houses in Canarsie, Brooklyn, and Rivera in the former Edgemere Houses in Far Rockaway, Queens.

Deploying the mobile boilers involves a team of other trades people — plumbers, electricians, carpenters, roofers — all involved in running pipes and other equipment from the mobile boilers into the existing boiler room.

Rivera adjusts settings on an oil burner in the mobile boiler on Tuesday.

“When these things get ripped out and they replace these boilers, we’ll cannibalize every usable part and save them for future use,” Knapp said.

But the real problem is that the boilers don’t typically get replaced. Each of the four humming in the humid boiler room of the Astoria Houses would cost about $2.5 million to replace — $10 million altogether, or almost all of the $13 million in extra cash the mayor has pledged. And the boilers, Acevedo said, are just the heart — the distribution system, which he likened to arteries, would need to be replaced too.

The biggest problem facing his team is the same issue that plagues all of NYCHA — a loss of federal subsidies, leaving the agency in dismal fiscal shape.

“It’s not because we don’t care. We are truly invested in this. We care. We personally understand. We all grew up in public housing, right?” he said, standing in the boiler room beside Acevedo and Rivera.

“There are families that depend on us to provide a service. And we do the best we can with what we have.”